#include <stdio.h>

#define M 100

#define CALC(x) (x * x)
/*
宏：原样替换
*/
int main () {

    printf(" M = %d \n", M);

    printf(" CALC() = %d \n", CALC(M + M)); // 100 + 100 * 100 + 100  = 10200 
    return 0;
}